Vertically Stratified Ash-Limb Beetle Fauna in Northern Ohio

摘要

To better understand the diversity and ecology of indigenous arthropods at risk from the invasive emerald ash borer (Agrilus planipennisFairmaire) in North American forests, saproxylic beetles (Insecta: Coleoptera) were reared from ash (Fraxinussp.) limbs suspended in the canopy,~10–17 m above the ground, and from those placed on the ground in a mature mixed hardwood forest. In total, 209 specimens from 9 families and 18 species were collected from 30.0 m2of limbs. The generalist cerambycidNeoclytus acuminatus(Fabricius) was the most commonly captured taxon, followed by an assemblage of four exotic ambrosia beetles dominated byXylosandrus crassiusculus(Motschulsky). Two species largely or entirely restricted to ash, the buprestidAgrilus subcinctusGory and the curculionidHylesinus aculeatus(Say), were collected as well. Although there were no differences in beetle richness, abundance, or density between limb positions, community composition differed significantly. This can be largely attributed to phloem and wood-feeding species (i.e., Cerambycidae and Buprestidae) being more common in the suspended limbs and ambrosia beetles being more numerous on the forest floor. Possible explanations for these patterns are discussed.